Soluble oil composition



Patented Dec. 14, 1948 SOLUBLE OIL COMPOSITION Robert M. Koppenhoefer, Jackson Heights, N. Y.,

assignor to Socony-Vacuum Oil Company, Incorporated, a corporation oi New York No Drawing. Application September 26, 1946, Serial No. 698,407

as calf upper, elk, garment sheep, glove, shearlings or dressed kidskin, and in the dressing of certain furs, such as muskrat or Persian lamb, the partially processed skin may be lubricated by milling in a water emulsion of a suitable oil or grease.

During this operation, known as fat-liquorlng, the oil is exhausted from the liquor and deposited upon the fibers oi? the skin in a manner which is related to the composition of the soluble 011 employed. This oil, in the finished leather, serves as a lubricant and contributes much to the quality and performance of the leather or fur so treated, Many types of soluble oil have been used for this purpose in the industry. These include sulfated fatty oils, sulfonated mineral oils, soaps, egg yolk and mixtures of these materials with untreated fatty or mineral oils. For some applications, such as processing chrome or vegetable-tanned leather, such mixtures serve satisfactorily under varying conditions of application.

However, for certain applications of leather or fur processing, these conventional oils are unsuitable. This is true in the case of alum-tanned leather where the leather has been tanned with one of the alum stalts, such as potassium-aluminum sulfate, in which case the tanning agent is held in a loosely bound union with the hide protein. The same type of tannage is often used on furs. Since these salts are easily removed from the leather, they offer difilcult lubricating problems because they precipitate all emulsifiers of the type previously listed and by rendering the emulsion unstable, they prevent an adequate penetration and take-up of oil by the leather and produce a poor quality product. In order to overcome this in the past, it has been customary to resort to extensive washing of the tanned leather or fur to remove most of the water-soluble alum, after which the leather could be lubricated by milling in a conventional oil emulsion with a fair degree of success. However, such continued preliminary washing is objectionable because, by

washing out the tanning extract, the degree .of tannage is reduced and consequently the quality of the finished product is reduced.

In accordance with the present invention, a soluble oil, stable in the presence of dissolved alum or other acidic electrolyte, which permits a not- 6 Claims. (01. 252-457) mal penetration and deposition of lubricating oil on the tanned skin or other fibrous surface has been discovered. By using said oil, it has been found that tanning and fat-liquoring of the leather to be treated may be carried out in a single operation by adding the fat-llquoring oil directly to the tan bath, thus eliminating several intermediate operations at a considerable saving in processing costs.

The emulsifiable oil composition of this invention, characterized by unusual stability in the presence of neutral or acidic electrolytes, that is, in mediums having a pH of below about 8, is particularly applicable in the fat-liquoring of alumtanned skins. In addition to an oil, the composition of this invention comprises a minor proportion of each of the following: a polyoxyalkyb ene derivative of a long chain fatty acid ester of hexitol anhydride, a rosin acid, a long chain fatty acid ester of hexitol anhydridc, a low molecular weight fatty acid, and a substituted glyoxalidine The combination of these substances, when added to a mineral oil, vegetable oil or blends thereof in such amounts that the final composition contains from about 25 to about 50 per cent by weight of these materials, yields a soluble oil, the emulsions of which are extremely stable in the presence of electrolytes.

More specifically, the present invention contemplates a leather processing oil comprising a major proportion of oil, from about 6 to about 10 percent by weight of a polyoxyallsylene derivative 05. a fatty acid ester of. a hexitol anhydride, said fatty acid having at least six carbon atoms; from about 6 to about 12 per cent by weight of a rosin acid; from about 1 to about 4 per cent by weight of a fatty acid ester of a hexitol anhydride, said fatty acid having at least six carbon atoms; from about 3 to about 6 per cent by weight of a low molecular weight fatty acid of less than five carbon atoms; and from about 10 to about 16 per cent by weight of a substituted glyoxalidine having the general formula:

wherein R1 is selected from the group consisting of alkyl and alkenyl radicals containing from 10 to 18 carbon atoms; R2 is an alkyl group containing less than five carbon atoms substituted with a radical X selected from the group consisting of hydroxyl and amino radicals. This particular combination of substances in the specific proportions given has been found to render oil emulgree of stability slightly less than those of the sions extremely stable to aluminum salts and Percentage by Weight Composition Example l-Hydroxy ethyl z-heptadecenyl glyoxalidine 10 10 10 l l0 l0 l8 l0 Hydrogenated rosin 8 8 8 8 8 12 8 Polyoxyalkylene derivative of Sorbitan monopalmitate 7 7 7 9 7 7 7 2 2 2 2 4 2 l6 16 lg l6 16 16 l6 16 I I I 4 f "6 I Mineral on (100 sec.) II is 48 is 15 '45" 19 55 "a Isopropyl alcohol 3 3 3 3 2 3 3 5 Triethanolamine 2 2 2 2 2 2 2 It will be noted that Examples 6 and 7 total 101 and 102 percent; actually, the parts are by weight in these examples, rather than in percent by weight. The examples, however, are substantially comparable.

Examples 1 and 2 are representative of the oil compositions of this invention and are characterized by a maximum degree of emulsion stability in the presence of high concentrations of acidic or neutral electrolytes. The composition of Example 1 has been stabilized using, in addition to the other components shown, acetic acid and is relatively non-corrosive to metals while the composition of Example 2, employing formic acid as one of its components is moderately corrosive to metals. The remaining examples show the need for each of the above-mentioned components in the specific proportions set forth above. The compositions of these examples were unsatisfactory, as will be shown below, for fat-liquoring alum-tanned leather. In Example 3, hydrogenated rosin was replaced by oleic acid. The resulting oil composition was unstable to alum (potassium aluminum sulfate), since insoluble aluminum oleates were formed. Thus, a fatty acid cannot be employed in place of the more stable rosin acid derivatives, such as hydrogenated rosin used in the compositions of Examples 1 and 2. The composition of Example 4, in which sorbitan monolaurate was omitted, was capable of forming emulsions but upon standing, a separation of the oil occurred therein showing the necessity of this component. In Example 5,. the composition was unsuitable because the excessive acetic acid content gave a decreased dispersion to the emulsions. In the composition of Example 6, an excess of sorbitan monolaurate was used. An emulsion employing such composition, upon standing, separated into layers, illustrating that amounts less than 4 per cent of this material should be used to impart a maximum degree of stability to the resulting emulsion. The formulation of Example '7, in which the polyoxyalkylene derivative of sorbitan monopalmitate and sorbitan monolaurate was omitted, yielded an emul sion which separated, on standing, into layers showing the stabilizing action of these two components. In the composition of Example 8, triethanolamine was omitted. The resulting emulsion employing such composition had a high denitan monopalmitate.

formulations of Examples 1 and 2. Thus, while trlethanolamine is not an essential component of the present oil composition, its presence in small amounts is to be preferred.

The above examples have shown a representative of each of the necessary groups of emulsifiers or stabilizers essential for the composition of the present invention. Various other members of each group may be so employed. Thus, in place of l-hydroxy ethyl, 2-heptadecenyl glyoxalidine, various other substituted glyoxalidines, such as l-amino ethyl, 2-heptadecenyl glyoxalidine, may be employed conforming to the type formula:

Bax

where R1 is an alkyl or alkenyl group containing from 10 to 18 carbon atoms, R2 is an alkyl group containing 1 to 5 carbon atoms and X is a hydroxyl or amino group. These substituted glyoxalidines, employed in an amount between about 10 and about 16 per cent by weight of the oil composition, have been found preferable for the stabilization of oil emulsions in the presence of electrolytes.

In place of hydrogenated rosin in the above compositions, other rosin derivatives or acids may be used. Thus, rosin, disproportionated rosin,

polymerized rosin or the various rosin acids, such as abietic, pimaric, and the like may be employed in percentages of between about 6 and about 12, based on the total weight of the oil formulation.

The polyoxalkylene derivative of sorbitan monopalmitate may be replaced by other polyoxyalkylene derivatives of hexitol anhydrideslong chain fattty acid esters, such as sorbitan monooleate, sorbitan monostcarate, mannitan monooleate, mannitan monostearate, and man- In general, the polyoxyalklylene chain of these compounds will contain not more than twenty oxide linkages. Likewise, the sorbitan monolaurate used in the examples may be replaced with other fatty acid-hexitol anhydride esters, such as those of myristic, palmitic, and oleic acids with hexitans, such as dulcitan, mannitan, and sorbitan.

In place of acetic acid used in the above formulations, any of the low molecular weight fatty acids up to five carbon atoms may be used, such as lactic, butyric, propionic, and isobutyric acids.

Triethanolamine, as stated above, is not an essential component of the present oil composition but is preferably present, lending greater stability to emulsions prepared from compositions containing the same. Likewise, isopropyl alcohol, while not an essential component of the above formulations, serves as a deodorant and to some extent as a clarifying agent. The oil employed a lubricant for leather or fur processing may be a vegetable or mineral oil or blends of the two as shown in the above examples, in which lard oil and a mineral oil were used with advantage.

The adequacy of the new type oil of this invention can be demonstrated by permitting emulsions of the oil compositions to come in contact with solutions of various electrolytes. The oil composition shown in Example 1 was diluted to ten times its volume with solutions of a wide variety of salts and acids as shown below and after standing at room temperature for two hours, the results are summarized below:

Electrolyte Stability Calcium Chloride, Sulfuric Acid, 10% Hydrochloric Acid, 10%. Acetic Acid, 10% Tap Water Do. StabIl)e, Slight Cream.

0. Stable, Trace Separation.

able.

From the above, it will be seen that emulsions of excellent stability to various electrolytes are obtained by the particular combination of emulsifiers in the oil composition of this invention.

Oil-in-water emulsions similar to those above may be prepared by mixing oil in water in proportions which vary from about two parts of oil to one part of water up to emulsions of infinite dilution with water. These emulsions are particularly valuable in the fat-liquoring treatment of leather or fur. This was demonstrated by employing the oil, according to the formulation of Example 1, to fat-liquor alum-tanned muskrat skins. After the tanning process was completed, a quantity of oil equal to per cent of the wet weight of skins was added directly to the alum tan liquor containing about 5 per cent by weight of aluminum sulfate and about 8 per cent by weight of sodium chloride. The oil emulsified easily. The skins were tumbled for four hours in the lubricating solution, removed and dried. A 50 per cent take-up of the oil was obtained and the skins were pliable and soft, giving a leather of fine quality without the tedious steps of washing the skins free of salts after treatment with alum tanning liquor.

Those skilled in the art will readily recognize the advantage of the above emulsifiable leather and fur processing oil; namely, that the stability of oil in the presence of electrolytes permits a normal penetration and deposition of the lubricant on the fiber surface and that alum tanning and fat-liquoring of the leather may be carried out in a single operation resulting in a product of better quality and with a considerable saving in equipment, time, and processing costs.

I claim:

1. An emulsifiable oil composition comprising: a major proportion of at least one oil suitable for fat liquoring, which oil is selected from the group consisting of animal, mineral and vegetable oils: from about 6 to about 12 per cent by weight of a rosin acid; from about 6 to about 10 per cent by weight of a polyoxyalkylene derivative of a fatty acid ester of a hexitol anhydride, said fatty acid having at least six carbon atoms; from about 1 to about 4 per cent by weight of a fatty acid ester of a hexitol anhydride, said fatty acid having at least six carbon atoms; from about 3 toabout 6 per cent by weight of a low molecular weight fatty acid of less than five carbon atoms; and from about 10 to about 16 per cent by weight of a compound having the general formula:

mama where R1 is selected from the group consisting of alkyl and alkenyl radicals containing from 10 to 18 carbon atoms and R: is an alkyl group containing 1 to 6 carbon atoms substituted with 8 radical selected from the group consisting of hydroxyl and amino radicals.

2. The composition defined in claim 1 wherein the rosin acid is a hydrogenated rosin.

3. The composition defined in claim 1 wherein the compound represented by the general formula is l-hydroxy ethyl, 2-heptadecenyl glyoxalidine. a

4. The composition defined in claim 1 wherein the compound represented by the general formula is l-amino ethyl, 2-heptadecenyl glyoxalidine.

5. An emulsifiable oil composition comprising: a major proportion of at least one oil suitable for fat liquoring, which oil is selected fromthe group consisting of animal, mineral and vegetable oils; from about 6 to about 12 per cent by weight of hydrogenated rosin; from about 6 to about 10 percent by weight of a polyoxyalkylene derivative of sorbitan monopalmitate; from about 1 to about 4 per cent by weight of sorbitan laurate; from about 3 to about 6 per cent by weight of a low molecular weight fatty acid of less than five carbon atoms; and from about 10 to about 16 per cent by weight of l-hydroxy ethyl, 2-heptadecenyl glyoxaiidine.

6. An emulsifiable oil composition comprising a major proportion of mineral oil, from about 6 to about 12 per cent by weight of a rosin acid; from about 6 to about 10 per cent by weight of a polyoxyalkylene derivative of a fatty acid ester of a,hexitol anhydride, said fatty acid having at least six carbon atoms; from about 1 to about 4 per cent by weight of a fatty acid ester of a hexitol anhydride, said fatty acid having at least six carbon atoms; from about 3 to about 6 per cent by weight of a low molecular weight fatty acid of less than five carbon atoms; and from about 10 to about 16 per cent by weight of a compound having the general formula:

I lhX Where R1 is selected from the group consisting of alkyl and alkenyl radicals containing from 10 to 18 carbon atoms and R2 is an alkyl group containing 1 to 5 carbon atoms substituted with a radical X selected from the group consisting of hydroxyl and amino radicals.

ROBERT M. KOPPENHOEFER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2, 2, Roth Apr. 3, 1945 FOREIGN PATENTS Number Country Date 416,309 Great Britian Dec. 5, 1932 OTHER REFERENCES "Bpans and Tweens"pamphlet pub.'1945, by Atlas Powder Co., of Wilmington, DeL-pages 1, 2, 12, 13, 14, and 15.

"Bpans and Tweenspamph1et pub. 1942, by Atlas Powder (30., of Wilmington, Del.page 1.

Davis-Manufacture of Leatherpub. 1885, by H. C. Baird and 00.. of Philadelphia-pages 658-868. 

